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[函数] 求教kuing一道向量题

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chr93918 Post time 2015-11-2 15:41 |Read mode
IMG_0686.JPG

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kuing Post time 2015-11-2 16:31
最大值是
\[\sqrt{\frac{229247}{1728}+\frac{17}{864} \sqrt{185380705} \cos \left(\frac{1}{3} \arctan\frac{82574422272 \sqrt{11946531}}{12397339678600511}\right)}\approx 20.013868988\]

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kuing Post time 2015-11-2 16:41
最小值为其相反数

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 Author| chr93918 Post time 2015-11-2 20:48
请教过程

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kuing Post time 2015-11-2 20:49
我的意思是叫你把这题扔掉。

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 Author| chr93918 Post time 2015-11-2 20:51
谢谢

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敬畏数学 Post time 2015-11-3 11:24
此题最后:9cosa+2(25+24sina)^1/2的最大值,a∈【0.2π】,如何进行下去。。。

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敬畏数学 Post time 2015-11-4 17:19
CM*CN=(CA+AM)(CB+BN)=CA*BN+CB*AM+AM*BN
AM*BN<=3*2,当AM与BN同向共线时等号成立。
CA*BN+CB*AM=4*2*sina+3*3cosa<=根号(81+64)=根号145
最大值为6+根号145.
最小值为-6-根号145

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kuing Post time 2015-11-4 17:28
回复 8# 敬畏数学

错。

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敬畏数学 Post time 2015-11-4 17:37
回复 9# kuing
请教指正!

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kuing Post time 2015-11-4 17:43
回复 10# 敬畏数学

不指正。
叫你们扔了这题你们不听,后果自负。

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第一章 Post time 2015-11-11 16:19
印象中至少一年前就在热议这个题了,当时都说题目有问题啊。
怎么最近又频繁出现了?

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kuing Post time 2015-11-11 16:32
回复 12# 第一章

木印象……

手机版|悠闲数学娱乐论坛(第3版)

2025-3-6 18:06 GMT+8

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